The Smartwool Women's Merino 150 Baselayer Tank is a lightweight tank for warm weather activity. Tie your shoes and whether you're hiking, running, biking or other, get outdoors and enjoy the heat. The Slim Fit top will cover your Upper half, while leaving arms free to soak up some sun. The merino wool and nylon core jersey fabric puts the merino next-to-skin, while the nylon core increases durability. Features of the Smartwool Women's Merino 150 Baselayer Tank Lightest weight Merino jersey fabric Uses a nylon core to increase durability while keeping Merino wool next to skin Classic racerback design Side seams wrap to front for body-enhancing Fit Stretch merrow stitching for comfort and a feminine aesthetic